Investigation of peri-implant diseases prevalence and related risk indicators in patients with treated severe periodontitis over 4 years after restoration

History of periodontitis is a well-documented risk indicator of peri-implantitis. However, the influence of severity of periodontitis is still unclear, especially for severe periodontitis. This study was aimed to investigate the prevalence of peri-implant disease and analyze the risk indicators in patients with treated severe periodontitis. A total of 182 implants from 88 patients (44 males and 44 females) with severe periodontitis with a mean fellow-up period of 76.5 months were enrolled in this study. Patient and implant information, and periodontal and peri-implant conditions were collected to evaluate the prevalence of peri-implant disease and risk indicators. The prevalence of peri-implantitis was 9.1% and 6.6% at the patient-level and implant-level. The prevalence of peri-implant mucositis was 76.1% and 51.1% at the patient-level and implant-level. Risk indicators of peri-implantitis included older age (OR: 1.132), poor proximal cleaning habits (OR: 14.218), implants in anterior area (OR: 10.36), poor periodontal disease control (OR: 12.76), high peri-implant plaque index (OR: 4.27), and keratinized tissue width (KTW)＜2 mm (OR: 19.203). Implants in patients with severe periodontitis after periodontal treatment and maintenance show a low prevalence (9.1%) of peri-implantitis and a relatively high prevalence (76.2%) of peri-implant mucositis. Patient age, peri-implant proximal cleaning habits, implant position, periodontal disease control, peri-implant plaque index, and KTW are associated with prevalence of peri-implantitis.